A short route to “reverse-prenylated” pyrrolo[2,3-b]indolesvia tandem olefination and claisen rearrangement of 2-(3,3-dimethylallyloxy)indol-3-ones: First total synthesis of flustramine C

Abstract The Wittig or Horner-Emmons reaction of 1-acetyl-2-(3,3-dimethylallyloxy)indol-3-ones proceeded via tandem olefination, isomerization, Claisen rearrangement, and deacetylation to give 3-cyanomethyl-3-(1,1-dimethylallyl)indol-2-ones in good yields, which were reduced with Red-Al ® to afford pyrrolo[2,3- b ]indoles having the 1,1-dimethylallyl group at the 3a-position. The first total synthesis of the marine alkaloid flustramine C was also described.